Fire-preventing device for motion-picture-projecting machines



Sept. 8, 1925; 1,553,050 G. J. SCHAFFER FIRE PREVENTING DEVICE FORMOTION PICTURE PROJECTING MACHINES Filed Sept. 15'. 1921 O ECD/PGE i 45m7, W/h,

Patented Sept. 8, 1925.-

unirsn srares PATENT OFFIQE.

GEORGE J. SCHAFFER, 015 LOS ANGELES, CALIFORNIA.

Application filed September 15, 1921.

To all who-m it may C(WLGGW/L-I Be it known that I, Grouse J.Soiriirrnn, a citizen oi": the United States, residing at Los Angeles,in the county of Los Angeles ant. tate of California, have invented newand useful Improvements in Fire-Preventing Devices forMotion-Picture-Projecting llIachines, of which the following is aspecification.

My invention relates to screen mechanism employed in Connection with theexposure opening of motion picture projecting apparatus, for closing theopening when the film strip breaks, thereby cutting off the beam oflight passing through the opening so as to prevent burning of the film.In screen mechanisms oi": this character heretotore proposed, they areso associated with the film strip as to close the exposure opening withinsufficient rapidity to actually prevent burning of the film strip,particularly when employing lamps of high candle power as is now thecommon practice.

It is a purpose of my invention to provide a screen mechanism which isassociated with any portion of the loop of a film strip or that portionbetween thev intermittent feed sprocket and the lower take-up sprocket,so that when the film strip breaks the screen mechanism will beimmediately released to close the exposure opening with the requiredrapidity to prevent the possibility of the film strip being ignited.

The invention will be readily understood from the following descriptionor the accompanying drawings, in which:

Figure 1 is a side elevation of a device constructed in accordance withthe inven tion, partly broken away.

Fig. 2 is a front elevation of an apparatus, partly broken away.

In the drawings I have shown a usual casing 1 adapted to carry themovable film strip and having an exposure opening 2 alined with the filmstrip and arranged in usual manner to receive the rays of light of theprojecting apparatus. The film strip 3 moves over the usual sprocketrollers 4 ll rough casing 1, and is also arranged to pass over rollerswhich are so positioned to form a horizontal flight 8 of the film strip.The casing is preferably provided with a usual hinged door 7 havingretaining Serial No. 500,897.

means 8 and preferably adapted to receive the horizontal flight of thefilm strip in the soace formed by said door which is a concavestructure.

A bracket 10 is arranged upon the inside or door 7 and carries asupporting rod 11 slidable tl'irough said bracket and having a roller 12at its lower end which rests upon the horizontal flight ot the filmstrip. The rod 11 extends upwardly beyond door 7 through a suitableopening 13 formed therein, and said supporting rod carries a screen 1 1-which is above exposure opening 2 when roller 12 rests upon the filmstrip so as to elevate the supporting rod.

The parts are so arranged that when the film breaks so as to releaseroller 12 and thereby permit dropping of the supporting red, the screenwill overlie the exposure opening and thereby eliminate the possibilityor lire. A collar 15 is adjustable along rod 11 and arranged to impingeagainst bracket 10 when the supporting rod and screen are lowered, asthus described. The collar thus forms a stop for limiting the movementof the supporting rod in order to properly aline the screen and theexposure opening.

It will be seen that I have provided an extremely simple but eilicientfire preventing means wherein a screen is automatically lowered toposition covering the exposure opening of the casing of a projectingmachine whenever a film, which is being exhibited, breaks.

Various changes may be made without departing from the spirit of theinvention as claimed.

What is claimed is 1. A motion picture projecting machine including acasing having an exposure opening, a door below said opening, a filmstrip movabl through the casing and across said exposure opening,supporting elements for said film strip arranged to form loop in thestrip below the exposure opening, a vertically disposed U-shaped bracketsecured within the door and hav the parallel portions thereof formedwith openings, a sup porting rod slidable in said openings and restingupon the loop of the lilm strip, and a screen carried by said rod andnormally positioned above the exposure opening. the

breaking of said film strip collapsing the loop and thereby releasingsaid supporting rod to permit the screen to drop into closing positionWith respect to the exposure opening.

2. A device of the character described comprising a bracket, a rodslidably sustained in the bracket, a roller carried by the rod, a screencarried by the rod, and means for limiting the movement of the rodthrough the bracket.

3. In a motion picture projecting apparatus, an exposure openingadjacent which the film is adapted to pass, a loop continuously formedby the advancing film, a portion of said loop resting upon guid rollersso as to form a substantially horizontal bight supported by saidrollers, a vertically slidable rod carrying a roller resting upon saidbight adapted to fall upon breaking of said film, and a screen actuatedby the falling of said rod for covering said exposure ope-nlng.

4. A device of the character described comprising a bracket, a rodslidably sustained in the bracket, a roller carried by the rod, a screencarried by the rod, and a collar adjustably secured to the rod forlimit- .ing the movement of the rod through the bracket.

5. A screen mechanism comprising a bracket, a rod slidable on thebracket, a screen carried by the upper end of the rod, a collar carriedby the lower end of the rod and adapted to rest on the loop portion of afilm strip disposed below th exposure opening of a motion pictureprojecting machine so as to normally hold the screen in nonclosingposition With respect to the exposure opening.

6. In a motion picture projecting apparatus, an exposure openingadjacent which the film is adapted to pass, a loop continuously formedby the advancing film, the lower portion of said loop resting upon guiderollers so as to form a substantially horizontal bight supported by saidrollers, a vertically slid-able rod carrying a roller resting upon saidbight adapted to :fall upon breaking of said film, and a screen actuatedby the talling of said rod for covering said exposure opening.

In testimony whereof I have signed my name to this specification.

GEO. J. SGHAFFER.

